Method for simulating and demonstrating the optical effects of glasses on the human face

• US 20030156125A1
• Filed: 03/24/2003
• Published: 08/21/2003
• Est. Priority Date: 02/13/2001
• Status: Active Grant

• Current Assignee: Rodenstock GmbH (Bridgepoint Advisers Group Limited)
• Original Assignee: Rodenstock GmbH (Bridgepoint Advisers Group Limited)
• Inventors: Altheimer, Helmut, Esser, Gregor, Welk, Andrea, Haimerl, Walter, Baumbach, Peter
• Granted Patent: US 6,965,385 B2
• Time in Patent Office: Days
• US Class Current: 345/629
• CPC Class Codes: G02C 13/003 Measuring during assembly or fitting of spectacles
• CPC Class Codes: G06T 11/00 2D [Two Dimensional] image generation
• CPC Class Codes: G09B 23/28 for medicine

Abstract

Described is a method for demonstrating an effect of a particular spectacle frame and of optical lenses fitted into this spectacle frame on the appearance of a spectacles wearer as it would be perceived by another person (virtual observer).

The invention comprises the following features:

preparing an image of a face of the spectacles wearer in such manner that the image can be processed in a computer;

determining an arrangement of the respective spectacle frame in front of the eyes,

projecting the image of the face onto a plane by means of a computation (ray-tracing) of principal rays passing through a center of rotation of an eye of the (virtual) observer, and thus producing a planar image of the face in this plane,

taking into account an optical power of a region, through which a principal ray passes, of each spectacle lens (virtually) fitted in the respective lens rim, and its arrangement in front of the eye in computing the paths of principal rays which lie within lens rims of the spectacle frame or edges of the spectacle lenses, so that an observer of the thus produced planar image of the face with “worn” spectacles can assess a distortion of the eyes portion of the face by the spectacle lenses and therewith a quality of the spectacle lenses.

Claims

1. Method for demonstrating an effect of a particular spectacle frame and of optical lenses fitted into this spectacle frame on an appearance of a spectacles wearer as it would be perceived by another person (virtual observer), comprising the following features:

preparing an image of a face of the spectacles wearer in such manner that the image can be processed in a computer;

determining an arrangement of the respective spectacle frame in front of the eyes,

projecting the image of the face onto a plane by means of a computation (ray-tracing) of principal rays passing through a center of rotation of an eye of the (virtual) observer, and thus producing a planar image of the face in this plane,

taking into account an optical power of a region, through which a principal ray passes, of each spectacle lens (virtually) fitted in a respective lens rim, and its arrangement in front of the eye in computing the paths of principal rays which lie within lens rims of the spectacle frame or edges of the spectacle lenses, so that an observer of the thus produced planar image of the face with “

worn”

spectacles can assess a distortion of the eyes portion of the face by the spectacle lenses and therewith a quality of the spectacle lenses.

2. Method according to claim 1,

characterized in that the computation of principal rays is performed for a so-called “

as worn”

position of the spectacle lens.

3. Method according to claim 1 or 2,

characterized in that the image of the face is a given image and, in particular, an image which is selectable from various standard images.

4. Method according to claim 1 or 2,

characterized in that the image of the face is a picture of a person recorded with an electronic image recorder.

5. Method according to claim 4,

characterized in that the picture of the person wishing to select a spectacle frame and/or spectacle lenses is used as an image.

6. Method according to claim 4 or 5,

characterized in that the picture is taken of the person wearing a spectacle frame.

7. Method according to any one of claims 1 to 5,

characterized in that the computer produces an image of the spectacle frame on the face of the represented person.

8. Method according to any one of claims 1 to 7,

characterized in that the image of the face is a two-dimensional image.

9. Method according to any one of claims 1 to 7,

characterized in that the image of the face is a three-dimensional image.

10. Method according to claim 9,

characterized in that various images of a face with different head positions are computed, and that a resulting series of images is demonstrated as a short film.

11. Method according to any one of claims 1 to 10,

characterized in that the image or images of the face are pixel images.

12. Method according to claim 11,

characterized in that only the pixel points at selected grid points are computed, and that intermediate pixel points are interpolated by a suitable method.

13. Method according to any one of claims 1 to 12,

characterized in that in addition to computing according to the ray-tracing method, a computation of wave-fronts (wave-tracing method) is made, which takes account of indistinct imaging by the spectacle lenses.

14. Method according to any one of claims 1 to 13,

characterized in that a reflection of principal rays of an arbitrarily positioned glaring-light source of arbitrary shape at a front and a back surface of the spectacle lenses is computed;

and

that reflection-images extending as far as the image plane are computed and traced in accordance with an intensity and a residual reflection color which depend on a coating and a refractive index and an Abbe number of a spectacle lens material.

15. Apparatus for performing the method according to any one of claims 1 to 14,

characterized in that the apparatus comprises

a supporting device for the image;

a supporting device for the spectacle lens;

a glaring-light source;

a supporting device for the face of the virtual observer; and

a computer for computing the principal rays.